a) Field of the Invention
Devices for adjusting lenses or lens groups within a lens system are known only in connection with high-performance lenses. In other cases, it is conventional to bring the optical axes of the individual lenses into agreement with the mechanical axis of the lens system housing by means of high-precision fabrication of the contact surfaces. Generally, the lenses are fixed in position by gluing. There is no possibility of subsequent readjustment in technical solutions of this kind.
b) Description of the Related Art
DD 206 591 B1 discloses a device in which a lens mount is arranged so as to be displaceable laterally in a holder which is pivotably suspended and adjustable at right angles to the device axis. The displacement of the lens mount Within the holder and the support of the mount are effected via the radially acting adjusting members. Since the adjusting members also function as supports, mechanical adjusting screws represent the only practicable adjusting means. They must all be loosened in order to carry out adjustment, so that the lens mount could slip during adjustment. Therefore, the optical axis must extend vertically during adjustment. Permanent positioning by means of adjusting members is unsuitable for especially large lens systems.
A comparable solution using lateral lens adjustment is described in OE-Reports, No. 67, p. 13, July 1989, published by SPIE. An auxiliary lens mount with two plane surfaces within which the lens is fixed is adjustable vertically to the optical axis via adjustment members in a second mount. The auxiliary mount lies on a plane surface of the second mount. There is a fit clearance or play for purposes of adjustment. However, in contrast to the first solution mentioned above, the adjusted position is fixed by applying glue.
DE PS 37 30 094 describes a device in which an auxiliary mount which is displaceable in a principal mount is pressed against a base surface indirectly by means of spring force acting vertically to the direction of displacement. The forces determining this clamping connection must be overcome for adjustment laterally to the optical axis.
In a device disclosed in DE OS 2 220 373 for centering eyeglasses, an ophthalmic lens which is displaceable laterally to the optical axis of the device is held between rigid pins which are securely connected with a support arm on the one hand and spring-mounted support rods on the other hand. Lateral displacement is effected manually and the clamping connections formed by the pins and support rods can be dissolved by pressing slightly against the support rods. Such a technical solution is not suited for adjusting lenses within lens systems.
JP 60-150016 discloses microcomputer-controlled lateral adjustment of lenses via piezoelectric translators. The lenses are fixed in position in this case, apparently after adjustment, by applying glue.